This application relates to the evaluation of power transmission conductors and, more particularly, to an apparatus and method for evaluating power transmission conductors.
Conductor life and reliability are of increasing concern to many utilities. Many thousands of miles of lines are now approaching an age in service that has been deemed to be an expected life (i.e., 50-70 years). As a result, core wire failures resulting in outages, property damage, and loss of revenue is now being experienced, and the consequences of such failure may be significant with widespread implications.
In many areas with environmentally benign conditions conductor life could be significantly longer, whereas in more aggressive environmental conditions (coastal areas, areas with significant industrial pollution, agricultural areas where fertilizers and pesticides are used, and areas with moderate to high annual precipitation) conductors may experience premature failures due to core corrosion. Corrosion of the core is a determinant for conductor life and the detection of this condition is difficult and expensive.
Condition assessment of power transmission conductors, such as aluminum conductor steel reinforced (ACSR) conductors, has traditionally been completed by removing a section of the conductor that is in service and performing a visual inspection on each individual strand. This often requires a power outage, a team of linemen, and a bucket truck with winches and cable cutters to remove the section. The loose ends are then spliced onto a length of new conductor and then tensioned back to the original specifications.
Accordingly, a cost-effective apparatus and method is needed to detect evidence of core wire corrosion to enable utilities to better assess conductor condition and remaining life, and plan for conductor replacements.